Abstract
Let ( X , τ ) be a topological space and p ̸∈ X. Put Xp = X ∪ { p }. Define a topology τ⋆ on Xp by τ⋆ = { ∅ } ∪ {U ∪ { p } : U ∈ τ }. The space ( Xp, τ⋆) is called the closed extension space of ( X , τ ). We present new results about the closed extension topological spaces. Mainly weaker versions of normality.